The present invention pertains to brake cylinders used with hydraulic braking systems and more particularly pertains to hydraulic brake master cylinders which can be much lighter in weight than those made of cast iron or steel, yet which are nonetheless able to satisfy stringent requirements of strength, reliability and durability.
Master cylinders used with the hydraulic braking systems of automobiles have been produced largely from cast iron which must be cast in molds. Upon removal from the molds, the iron castings are somewhat rough, and considerable postcasting machining must be resorted to in producing a finished product. The cylinder bore for one or more hydraulic pistons must be reamed to the desired size and tolerance, various holes and/or channels must be drilled in the casting, and openings for pressure tubing must be tapped to provide threads. Although steps are taken to reduce costs, considerable time and effort are nonetheless required to finish a master cylinder, and the relatively thick casting of iron is quite heavy, difficult to handle, and is significantly contributory to the total weight of an automobile on which the cylinder is mounted.
The automotive industry has become increasingly involved with the problem of reducing the weight of automobiles in order to satisfy customer expectations as regards size, performance, price and operating cost while also anticipating or conforming to government regulations on safety, emissions, and gasoline mileage. As a consequence, the automobile designer is frequently confronted with a dilemma when consumer desires and laws designed to protect the consumer are in conflict with each other. It is therefore oftentimes difficult for the manufacturer to find ways for reducing the weight of an automobile without compromising safety or increasing manufacturing costs.
Discovery of a safe and economical way to reduce the total weight of a car by only a fraction of a percent is important in view of the fact that a number of such discoveries can result in a considerable reduction in total weight.
A principal object of the present invention is, therefore, to provide an improved hydraulic brake master cylinder whereby the aforementioned disadvantages associated with manufacture and use of cast iron master cylinders is alleviated.
Another object is to provide an improved hydraulic brake master cylinder that is lighter in weight yet strong and serviceable.
Still another object is to provide a master cylinder of lighter weight whereby the total weight of a vehicle to which the cylinder is attached can be reduced.
Yet another object is to provide a master cylinder having improved features and which can be produced more easily and at lower cost than cast iron master cylinders.
Even another object is to provide a method for producing a master cylinder whereby machining thereon following a casting operation is reduced or eliminated.
Another object is to provide an improved master cylinder by using metals which can be diecast in forming integral component parts of the cylinder.
These and other objects and advantages of the invention will become apparent from the following description and the appended claims.